Description (Adapted from application): This laboratory was established as a component of the DRTC in 1977. It is supervised by Dr. Charles Rubin and is currently staffed by a highly skilled half-time cell culture technician. The core laboratory grows, maintains and stores a variety of cell lines suitable for investigations on: (1) the J regulation of polypeptide hormone secretion; (2) the development, regulation and function of insulin and IGF-I receptors, receptors for other polypeptide hormones and growth factors and catecholamines; (3) the regulation of gene expression by insulin, other hormones and cytokines; (4) the biochemistry and cell biology of prohormone processing and intracellular targeting of prohormones; (5) the roles of protein kineses and protein l phosphorylation in hormone action; (6) control of glucose and amino acid transport by insulin, IGF-I and other agents; (7) cellular and molecular mechanisms governing the expression of glucose transporter isoforms; (8) the intracellular targeting of cAMP signaling. Cells and technical expertise are also provided for the development of eukaryotic systems that express high levels of recombinant proteins. The Cell Culture Facility also prepares, sterilizes, distributes and tests the quality of large batches of cell media. Phosphate buffered saline, drugs, hormones and metabolic inhibitors are prepared, sterilized and tested as dictated by the needs of individual experiments. Special media formulated for metabolic labeling experiments are also prepared and distributed when requests are received from two or more investigators. Fetal calf, calf and horse sera, screened for high plating efficiency and efficacy in supporting cell growth are provided by the core laboratory. Batches of fetal calf serum which have been pre tested and selected for maximum efficacy in supporting cell differentiation are also available. The Cell Culture Core Component provided support for the following investigators and projects during the previous grant period. B. Molecular Biology Component The Molecular Biology Core facility was established and united with the pre-existing Cell Culture Core facility in 1987. It is directed by Charles Rubin with the assistance of Dennis Shields (associate director). The director, associate director and a full time molecular biology technician provide services, training and expertise.